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Deep phenotyping of 89 xeroderma pigmentosum patients reveals unexpected heterogeneity dependent on the precise

Hiva Fassihi1, Mieran Sethi2, Heather Fawcett3

  • 1National Xeroderma Pigmentosum Service, Department of Photodermatology, St John's Institute of Dermatology, Guy's and St Thomas' Foundation Trust, London SE1 7EH, United Kingdom; a.r.lehmann@sussex.ac.uk Hiva.Fassihi@gstt.nhs.uk.

Proceedings of the National Academy of Sciences of the United States of America
|February 18, 2016
PubMed

Insights

Xeroderma pigmentosum (XP) is a rare DNA repair disorder with significant clinical variability. This study highlights unexpected heterogeneity in XP patient features, impacting prognosis and management strategies.

Area of Science:

  • Genetics
  • Dermatology
  • Neurology

Background:

  • Xeroderma pigmentosum (XP) is a rare genetic disorder impacting DNA repair, leading to UV sensitivity, skin cancer, and neurological issues.
  • XP is classified into eight genetic complementation groups (XP-A to -G and variant).
  • Previous understanding suggested milder forms in certain XP groups based on cellular analysis.

Purpose of the Study:

  • To investigate the clinical heterogeneity within a large cohort of UK Xeroderma pigmentosum patients.
  • To correlate genetic complementation groups and specific mutations with clinical manifestations.
  • To provide personalized prognostic information and management strategies for XP patients.

Main Methods:

  • Long-term follow-up of 89 XP patients in the UK national multidisciplinary service.
  • Deep phenotyping, measuring causative mutations, DNA repair levels, and over 60 clinical variables.
  • Utilizing scoring systems to categorize disease severity across dermatology, ophthalmology, and neurology.

Main Results:

  • Identified significant clinical heterogeneity in XP patients, both between and within complementation groups.
  • XP-C, XP-E, and XP-V patients showed higher skin cancer rates than previously thought, often diagnosed later due to normal sunburn reactions.
  • XP-C patients exhibit ocular hypersensitivity, while XP-F and XP-G patients appear less prone to skin cancer. Specific mutations influence neurological damage susceptibility.

Conclusions:

  • Xeroderma pigmentosum is more clinically heterogeneous than previously appreciated.
  • Deep phenotyping provides crucial insights into XP's diverse clinical spectrum.
  • Findings enable personalized prognostic information and tailored management plans for XP patients, advancing understanding of XP protein functions.
Keywords:
UV radiationneurodegenerationnucleotide excision repairocular diseaseskin cancer

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